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Middelkoop TC, Neipel J, Cornell CE, Naumann R, Pimpale LG, Jülicher F, Grill SW. A cytokinetic ring-driven cell rotation achieves Hertwig's rule in early development. Proc Natl Acad Sci U S A 2024; 121:e2318838121. [PMID: 38870057 PMCID: PMC11194556 DOI: 10.1073/pnas.2318838121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Accepted: 05/03/2024] [Indexed: 06/15/2024] Open
Abstract
Hertwig's rule states that cells divide along their longest axis, usually driven by forces acting on the mitotic spindle. Here, we show that in contrast to this rule, microtubule-based pulling forces in early Caenorhabditis elegans embryos align the spindle with the short axis of the cell. We combine theory with experiments to reveal that in order to correct this misalignment, inward forces generated by the constricting cytokinetic ring rotate the entire cell until the spindle is aligned with the cell's long axis. Experiments with slightly compressed mouse zygotes indicate that this cytokinetic ring-driven mechanism of ensuring Hertwig's rule is general for cells capable of rotating inside a confining shell, a scenario that applies to early cell divisions of many systems.
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Affiliation(s)
- Teije C. Middelkoop
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307Dresden, Germany
- Laboratory of Developmental Mechanobiology, Division Biocev, Institute of Molecular Genetics of the Czech Academy of Sciences, 14220Prague, Czech Republic
| | - Jonas Neipel
- Max Planck Institute for the Physics of Complex Systems, 01187Dresden, Germany
| | - Caitlin E. Cornell
- Department of Bioengineering, University of California, Berkeley, CA94720
| | - Ronald Naumann
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307Dresden, Germany
| | - Lokesh G. Pimpale
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307Dresden, Germany
| | - Frank Jülicher
- Max Planck Institute for the Physics of Complex Systems, 01187Dresden, Germany
- Cluster of Excellence Physics of Life, Technical University Dresden, 01062Dresden, Germany
| | - Stephan W. Grill
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307Dresden, Germany
- Cluster of Excellence Physics of Life, Technical University Dresden, 01062Dresden, Germany
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2
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Kashir J, Mistry BV, Rajab MA, BuSaleh L, Abu-Dawud R, Ahmed HA, Alharbi S, Nomikos M, AlHassan S, Coskun S, Assiri AM. The mammalian sperm factor phospholipase C zeta is critical for early embryo division and pregnancy in humans and mice. Hum Reprod 2024; 39:1256-1274. [PMID: 38670547 PMCID: PMC11145019 DOI: 10.1093/humrep/deae078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 03/13/2024] [Indexed: 04/28/2024] Open
Abstract
STUDY QUESTION Are sperm phospholipase C zeta (PLCζ) profiles linked to the quality of embryogenesis and pregnancy? SUMMARY ANSWER Sperm PLCζ levels in both mouse and humans correlate with measures of ideal embryogenesis whereby minimal levels seem to be required to result in successful pregnancy. WHAT IS KNOWN ALREADY While causative factors underlying male infertility are multivariable, cases are increasingly associated with the efficacy of oocyte activation, which in mammals occurs in response to specific profiles of calcium (Ca2+) oscillations driven by sperm-specific PLCζ. Although sperm PLCζ abrogation is extensively linked with human male infertility where oocyte activation is deficient, less is clear as to whether sperm PLCζ levels or localization underlies cases of defective embryogenesis and failed pregnancy following fertility treatment. STUDY DESIGN, SIZE, DURATION A cohort of 54 couples undergoing fertility treatment were recruited at the assisted reproductive technology laboratory at the King Faisal Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia. The recruitment criteria for males was a minimum sperm concentration of 5×106 sperm/ml, while all female patients had to have at least five oocytes. Sperm PLCζ analysis was performed in research laboratories, while semen assessments were performed, and time-lapse morphokinetic data were obtained, in the fertility clinic as part of routine treatment. The CRISPR/Cas9 system was concurrently used to induce indels and single-nucleotide mutations within the Plcζ gene to generate strains of Plcζ mutant mice. Sperm PLCζ was evaluated using immunofluorescence and immunoblotting with an antibody of confirmed consistent specificity against PLCζ. PARTICIPANTS/MATERIALS, SETTING, METHODS We evaluated PLCζ profiles in sperm samples from 54 human couples undergoing fertility treatment in the context of time-lapse morphokinetic analysis of resultant embryos, correlating such profiles to pregnancy status. Concurrently, we generated two strains of mutant Plcζ mice using CRISPR/Cas9, and performed IVF with wild type (WT) oocytes and using WT or mutant Plcζ sperm to generate embryos. We also assessed PLCζ status in WT and mutant mice sperm in the context of time-lapse morphokinetic analysis and breeding outcomes. MAIN RESULTS AND THE ROLE OF CHANCE A significant (P ≤ 0.05) positive relationship was observed between both PLCζ relative fluorescence and relative density with the times taken for both the second cell division (CC2) (r = 0.26 and r = 0.43, respectively) and the third cell division (S2) (r = 0.26). Examination of localization patterns also indicated significant correlations between the presence or absence of sperm PLCζ and CC2 (r = 0.27 and r = -0.27, respectively; P ≤ 0.025). Human sperm PLCζ levels were at their highest in the ideal times of CC2 (8-12 h) compared to time ranges outside the ideal timeframe (<8 and >12 h) where levels of human sperm PLCζ were lower. Following assignment of PLCζ level thresholds, quantification revealed a significantly higher (P ≤ 0.05) rate of successful pregnancy in values larger than the assigned cut-off for both relative fluorescence (19% vs 40%, respectively) and relative density (8% vs 54%, respectively). Immunoblotting indicated a single band for PLCζ at 74 kDa in sperm from WT mice, while a single band was also observed in sperm from heterozygous of Plcζ mutant mouse sperm, but at a diminished intensity. Immunofluorescent analysis indicated the previously reported (Kashir et al., 2021) fluorescence patterns in WT sperm, while sperm from Plcζ mutant mice exhibited a significantly diminished and dispersed pattern at the acrosomal region of the sperm head. Breeding experiments indicated a significantly reduced litter size of mutant Plcζ male mice compared to WT mice, while IVF-generated embryos using sperm from mutant Plcζ mice exhibited high rates of polyspermy, and resulted in significantly reduced numbers of these embryos reaching developmental milestones. LIMITATIONS, REASONS FOR CAUTION The human population examined was relatively small, and should be expanded to examine a larger multi-centre cohort. Infertility conditions are often multivariable, and it was not possible to evaluate all these in human patients. However, our mutant Plcζ mouse experiments do suggest that PLCζ plays a significant role in early embryo development. WIDER IMPLICATIONS OF THE FINDINGS We found that minimal levels of PLCζ within a specific range were required for optimal early embryogenesis, correlating with increased pregnancy. Levels of sperm PLCζ below specific thresholds were associated with ineffective embryogenesis and lower pregnancy rates, despite eliciting successful fertilization in both mice and humans. To our knowledge, this represents the first time that PLCζ levels in sperm have been correlated to prognostic measures of embryogenic efficacy and pregnancy rates in humans. Our data suggest for the first time that the clinical utilization of PLCζ may stand to benefit not just a specific population of male infertility where oocyte activation is completely deficient (wherein PLCζ is completely defective/abrogated), but also perhaps the larger population of couples seeking fertility treatment. STUDY FUNDING/COMPETING INTEREST(S) J.K. is supported by a faculty start up grant awarded by Khalifa University (FSU-2023-015). This study was also supported by a Healthcare Research Fellowship Award (HF-14-16) from Health and Care Research Wales (HCRW) to J.K., alongside a National Science, Technology, and Innovation plan (NSTIP) project grant (15-MED4186-20) awarded by the King Abdulaziz City for Science and Technology (KACST) for J.K. and A.M.A. The authors declare no conflicts of interest. TRIAL REGISTRATION NUMBER N/A.
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Affiliation(s)
- Junaid Kashir
- Department of Biological Sciences, College of Medicine and Health Sciences, Khalifa University, Abu Dhabi, United Arab Emirates
- Center for Biotechnology, Khalifa University, Abu Dhabi, United Arab Emirates
- Department of Comparative Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Bhavesh V Mistry
- Department of Comparative Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Mohamed A Rajab
- Department of Comparative Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Lujain BuSaleh
- Department of Comparative Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
- College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | - Raed Abu-Dawud
- Department of Comparative Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
- Institute for Molecular Medicine, MSH Medical School, Hamburg, Germany
| | - Hala A Ahmed
- Department of Comparative Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Sarah Alharbi
- Department of Pathology and Laboratory Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Michail Nomikos
- College of Medicine, QU Health, Qatar University, Doha, Qatar
| | - Saad AlHassan
- Department of Obstetrics and Gynaecology, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Serdar Coskun
- College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
- Department of Pathology and Laboratory Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Abdullah M Assiri
- Department of Comparative Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
- College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
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Blanchard GB, Scarpa E, Muresan L, Sanson B. Mechanical stress combines with planar polarised patterning during metaphase to orient embryonic epithelial cell divisions. Development 2024; 151:dev202862. [PMID: 38639390 PMCID: PMC11165716 DOI: 10.1242/dev.202862] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Accepted: 04/02/2024] [Indexed: 04/20/2024]
Abstract
The planar orientation of cell division (OCD) is important for epithelial morphogenesis and homeostasis. Here, we ask how mechanics and antero-posterior (AP) patterning combine to influence the first divisions after gastrulation in the Drosophila embryonic epithelium. We analyse hundreds of cell divisions and show that stress anisotropy, notably from compressive forces, can reorient division directly in metaphase. Stress anisotropy influences the OCD by imposing metaphase cell elongation, despite mitotic rounding, and overrides interphase cell elongation. In strongly elongated cells, the mitotic spindle adapts its length to, and hence its orientation is constrained by, the cell long axis. Alongside mechanical cues, we find a tissue-wide bias of the mitotic spindle orientation towards AP-patterned planar polarised Myosin-II. This spindle bias is lost in an AP-patterning mutant. Thus, a patterning-induced mitotic spindle orientation bias overrides mechanical cues in mildly elongated cells, whereas in strongly elongated cells the spindle is constrained close to the high stress axis.
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Affiliation(s)
- Guy B Blanchard
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3DY, UK
| | - Elena Scarpa
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3DY, UK
| | - Leila Muresan
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3DY, UK
- Cambridge Advanced Imaging Centre, University of Cambridge, Downing Street, Cambridge CB2 3DY, UK
| | - Bénédicte Sanson
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3DY, UK
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4
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Lamba A, Zernicka-Goetz M. The role of polarization and early heterogeneities in the mammalian first cell fate decision. Curr Top Dev Biol 2023; 154:169-196. [PMID: 37100517 DOI: 10.1016/bs.ctdb.2023.02.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/28/2023]
Abstract
The first cell fate decision is the process by which cells of an embryo take on distinct lineage identities for the first time, representing the beginning of patterning during development. In mammals, this process separates an embryonic inner cell mass lineage (future new organism) from an extra-embryonic trophectoderm lineage (future placenta), and in the mouse, this is classically attributed to the consequences of apical-basal polarity. The mouse embryo acquires this polarity at the 8-cell stage, indicated by cap-like protein domains on the apical surface of each cell; those cells which retain polarity over subsequent divisions are specified as trophectoderm, and the rest as inner cell mass. Recent research has advanced our knowledge of this process - this review will discuss mechanisms behind the establishment of polarity and distribution of the apical domain, different factors affecting the first cell fate decision including heterogeneities between cells of the very early embryo, and the conservation of developmental mechanisms across species, including human.
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Affiliation(s)
- Adiyant Lamba
- Mammalian Embryo and Stem Cell Group, Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Magdalena Zernicka-Goetz
- Mammalian Embryo and Stem Cell Group, Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom; Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, United States.
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5
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Fan XY, Wang XH, Xie FY, Ma JY, Ou XH, Luo SM. Cytokinesis During the First Division of a Mouse Embryo. Front Cell Dev Biol 2022; 9:815599. [PMID: 35178404 PMCID: PMC8843819 DOI: 10.3389/fcell.2021.815599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 12/24/2021] [Indexed: 11/28/2022] Open
Abstract
Cell division consists of nuclear division (mitosis for somatic cells and meiosis for germ cells) and cytoplasmic division (cytokinesis). Embryonic developments are highly programmed, and thus, each cellular event during early embryo development is stable. For mouse embryos, the first time of mitosis is completed about 22 h after fertilization. However, it remains unclear when the embryo completes its first cytokinesis. Here, we microinjected only one cell in the 2-cell stage mouse embryos with mRNA, which encodes green fluorescence protein (GFP). By monitoring the GFP protein transport dynamics between the two cells, we demonstrated that the first time of cytokinesis in mouse embryos is completed about 15 h after mitosis, namely 37 h after fertilization. In addition, our results indicate that the cytoplasmic protein transport between daughter cells is very effective, which relies on microtubules instead of microfilaments in 2-cell mouse embryos. These results should enrich people’s understanding of the first cell division and cytoskeleton in mouse embryos and then learn more about the mechanisms of early embryo development in mammals.
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Affiliation(s)
- Xiao-Yan Fan
- Fertility Preservation Lab, Reproductive Medicine Center, Guangdong Second Provincial General Hospital, Guangzhou, China.,Guangdong-Hong Kong Metabolism & Reproduction Joint Laboratory, Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Xing-Hua Wang
- Fertility Preservation Lab, Reproductive Medicine Center, Guangdong Second Provincial General Hospital, Guangzhou, China.,Guangdong-Hong Kong Metabolism & Reproduction Joint Laboratory, Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Feng-Yun Xie
- Fertility Preservation Lab, Reproductive Medicine Center, Guangdong Second Provincial General Hospital, Guangzhou, China.,Guangdong-Hong Kong Metabolism & Reproduction Joint Laboratory, Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Jun-Yu Ma
- Fertility Preservation Lab, Reproductive Medicine Center, Guangdong Second Provincial General Hospital, Guangzhou, China.,Guangdong-Hong Kong Metabolism & Reproduction Joint Laboratory, Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Xiang-Hong Ou
- Fertility Preservation Lab, Reproductive Medicine Center, Guangdong Second Provincial General Hospital, Guangzhou, China.,Guangdong-Hong Kong Metabolism & Reproduction Joint Laboratory, Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Shi-Ming Luo
- Fertility Preservation Lab, Reproductive Medicine Center, Guangdong Second Provincial General Hospital, Guangzhou, China.,Guangdong-Hong Kong Metabolism & Reproduction Joint Laboratory, Guangdong Second Provincial General Hospital, Guangzhou, China
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6
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Pomp O, Lim HYG, Skory RM, Moverley AA, Tetlak P, Bissiere S, Plachta N. A monoastral mitotic spindle determines lineage fate and position in the mouse embryo. Nat Cell Biol 2022; 24:155-167. [PMID: 35102267 DOI: 10.1038/s41556-021-00826-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 11/30/2021] [Indexed: 12/11/2022]
Abstract
During mammalian development, the first asymmetric cell divisions segregate cells into inner and outer positions of the embryo to establish the pluripotent and trophectoderm lineages. Typically, polarity components differentially regulate the mitotic spindle via astral microtubule arrays to trigger asymmetric division patterns. However, early mouse embryos lack centrosomes, the microtubule-organizing centres (MTOCs) that usually generate microtubule asters. Thus, it remains unknown whether spindle organization regulates lineage segregation. Here we find that heterogeneities in cell polarity in the early 8-cell-stage mouse embryo trigger the assembly of a highly asymmetric spindle organization. This spindle arises in an unusual modular manner, forming a single microtubule aster from an apically localized, non-centrosomal MTOC, before joining it to the rest of the spindle apparatus. When fully assembled, this 'monoastral' spindle triggers spatially asymmetric division patterns to segregate cells into inner and outer positions. Moreover, the asymmetric inheritance of spindle components causes differential cell polarization to determine pluripotent versus trophectoderm lineage fate.
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Affiliation(s)
- Oz Pomp
- Department of Cell and Developmental Biology, Institute for Regenerative Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Hui Yi Grace Lim
- Institute of Molecular and Cell Biology, ASTAR, Singapore, Singapore
| | - Robin M Skory
- Department of Cell and Developmental Biology, Institute for Regenerative Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Adam A Moverley
- Department of Cell and Developmental Biology, Institute for Regenerative Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Piotr Tetlak
- Department of Cell and Developmental Biology, Institute for Regenerative Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Stephanie Bissiere
- Department of Cell and Developmental Biology, Institute for Regenerative Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Nicolas Plachta
- Department of Cell and Developmental Biology, Institute for Regenerative Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
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7
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Simerly CR, Takahashi D, Jacoby E, Castro C, Hartnett C, Hewitson L, Navara C, Schatten G. Fertilization and Cleavage Axes Differ In Primates Conceived By Conventional (IVF) Versus Intracytoplasmic Sperm Injection (ICSI). Sci Rep 2019; 9:15282. [PMID: 31653971 PMCID: PMC6814755 DOI: 10.1038/s41598-019-51815-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Accepted: 10/03/2019] [Indexed: 12/14/2022] Open
Abstract
With nearly ten million babies conceived globally, using assisted reproductive technologies, fundamental questions remain; e.g., How do the sperm and egg DNA unite? Does ICSI have consequences that IVF does not? Here, pronuclear and mitotic events in nonhuman primate zygotes leading to the establishment of polarity are investigated by multidimensional time-lapse video microscopy and immunocytochemistry. Multiplane videos after ICSI show atypical sperm head displacement beneath the oocyte cortex and eccentric para-tangential pronuclear alignment compared to IVF zygotes. Neither fertilization procedure generates incorporation cones. At first interphase, apposed pronuclei align obliquely to the animal-vegetal axis after ICSI, with asymmetric furrows assembling from the male pronucleus. Furrows form within 30° of the animal pole, but typically, not through the ICSI injection site. Membrane flow drives polar bodies and the ICSI site into the furrow. Mitotic spindle imaging suggests para-tangential pronuclear orientation, which initiates random spindle axes and minimal spindle:cortex interactions. Parthenogenetic pronuclei drift centripetally and assemble astral spindles lacking cortical interactions, leading to random furrows through the animal pole. Conversely, androgenotes display cortex-only pronuclear interactions mimicking ICSI. First cleavage axis determination in primates involves dynamic cortex-microtubule interactions among male pronuclei, centrosomal microtubules, and the animal pole, but not the ICSI site.
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Affiliation(s)
- Calvin R Simerly
- Pittsburgh Development Center, Division of Developmental & Regenerative Medicine, and Obstetrics-Gynecology-Reproductive Sciences, Cell Biology, and Bioengineering, University of Pittsburgh Cancer Institute, University of Pittsburgh School of Medicine, 204 Craft Avenue Pittsburgh, Pennsylvania, 15213, USA
| | - Diana Takahashi
- Division of Cardiometabolic Health, Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, Oregon, 97006, USA
| | - Ethan Jacoby
- CCRM Houston Main Center Memorial City, 929 Gessner Rd, Suite 2300, Houston, Texas, 77024, USA
| | - Carlos Castro
- Pittsburgh Development Center, Division of Developmental & Regenerative Medicine, and Obstetrics-Gynecology-Reproductive Sciences, Cell Biology, and Bioengineering, University of Pittsburgh Cancer Institute, University of Pittsburgh School of Medicine, 204 Craft Avenue Pittsburgh, Pennsylvania, 15213, USA
| | - Carrie Hartnett
- Pittsburgh Development Center, Division of Developmental & Regenerative Medicine, and Obstetrics-Gynecology-Reproductive Sciences, Cell Biology, and Bioengineering, University of Pittsburgh Cancer Institute, University of Pittsburgh School of Medicine, 204 Craft Avenue Pittsburgh, Pennsylvania, 15213, USA
| | - Laura Hewitson
- The Johnson Center for Child Health and Development, Austin, Texas, 78701, USA
| | - Christopher Navara
- Department of Biology, South Texas Center for Emerging Infectious Disease, University of Texas at San Antonio, San Antonio, Texas, 78249, USA
| | - Gerald Schatten
- Pittsburgh Development Center, Division of Developmental & Regenerative Medicine, and Obstetrics-Gynecology-Reproductive Sciences, Cell Biology, and Bioengineering, University of Pittsburgh Cancer Institute, University of Pittsburgh School of Medicine, 204 Craft Avenue Pittsburgh, Pennsylvania, 15213, USA.
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8
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Finegan TM, Bergstralh DT. Division orientation: disentangling shape and mechanical forces. Cell Cycle 2019; 18:1187-1198. [PMID: 31068057 PMCID: PMC6592245 DOI: 10.1080/15384101.2019.1617006] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Revised: 04/05/2019] [Accepted: 04/12/2019] [Indexed: 12/12/2022] Open
Abstract
Oriented cell divisions are essential for the generation of cell diversity and for tissue shaping during morphogenesis. Cells in tissues are mechanically linked to their neighbors, upon which they impose, and from which they experience, physical force. Recent work in multiple systems has revealed that tissue-level physical forces can influence the orientation of cell division. A long-standing question is whether forces are communicated to the spindle orienting machinery via cell shape or directly via mechanosensing intracellular machinery. In this article, we review the current evidence from diverse model systems that show spindles are oriented by tissue-level physical forces and evaluate current models and molecular mechanisms proposed to explain how the spindle orientation machinery responds to extrinsic force.
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Affiliation(s)
- Tara M. Finegan
- Department of Biology, University of Rochester, Rochester, NY, USA
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9
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Chen Q, Shi J, Tao Y, Zernicka-Goetz M. Tracing the origin of heterogeneity and symmetry breaking in the early mammalian embryo. Nat Commun 2018; 9:1819. [PMID: 29739935 PMCID: PMC5940674 DOI: 10.1038/s41467-018-04155-2] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Accepted: 04/06/2018] [Indexed: 01/02/2023] Open
Abstract
A fundamental question in developmental and stem cell biology concerns the origin and nature of signals that initiate asymmetry leading to pattern formation and self-organization. Instead of having prominent pre-patterning determinants as present in model organisms (worms, sea urchin, frog), we propose that the mammalian embryo takes advantage of more subtle cues such as compartmentalized intracellular reactions that generate micro-scale inhomogeneity, which is gradually amplified over several cellular generations to drive pattern formation while keeping developmental plasticity. It is therefore possible that by making use of compartmentalized information followed by its amplification, mammalian embryos would follow general principle of development found in other organisms in which the spatial cue is more robustly presented.
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Affiliation(s)
- Qi Chen
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV, 89557, USA
| | - Junchao Shi
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV, 89557, USA
| | - Yi Tao
- Center for Computational and Evolutionary Biology, Institute of Zoology, Chinese Academy of Sciences, 100101, Beijing, China
| | - Magdalena Zernicka-Goetz
- Mammalian Development and Stem Cell Group, Department of Physiology, Development & Neuroscience, University of Cambridge, Downing Street, Cambridge, CB2 3EG, UK.
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10
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Southern HM, Berger MA, Young PG, Snook RR. Sperm morphology and the evolution of intracellular sperm-egg interactions. Ecol Evol 2018; 8:5047-5058. [PMID: 29876080 PMCID: PMC5980432 DOI: 10.1002/ece3.4027] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Revised: 02/16/2018] [Accepted: 02/26/2018] [Indexed: 01/06/2023] Open
Abstract
Sperm morphology is incredibly diverse, even among closely related species, yet the coevolution between males and females of fertilization recognition systems is necessary for successful karyogamy (male and female pronuclear fusion). In most species, the entire sperm enters the egg during fertilization so sperm morphological diversity may impact the intracellular sperm-egg interactions necessary for karyogamy. We quantified morphological variation of sperm inside eggs prior to and following karyogamy in several species of Drosophila to understand whether evolution of sperm morphology could influence intracellular sperm-egg interactions (ISEIs). We measured seven parameters that describe ISEIs among species to determine whether these parameters varied both within a species across development and across species at the same developmental stage. We used heterospecific crosses to test the relative role of male origin, female origin, and interaction between the male and female in determining ISEIs. We found that sperm shape changed within a species as development proceeded and, at particular development stages, species varied in some ISEIs. Parental origin had an effect on some ISEIs, with a general trend for a stronger female effect. Overall, our findings identify conserved and variable ISEIs among species and demonstrate the potential to contribute understanding to gamete evolution and development.
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Affiliation(s)
- Helen M. Southern
- Department of Animal and Plant SciencesUniversity of SheffieldSheffieldUK
| | | | - Philippe G. Young
- College of Engineering, Mathematics, and Physical SciencesUniversity of ExeterExeterUK
| | - Rhonda R. Snook
- Department of Animal and Plant SciencesUniversity of SheffieldSheffieldUK
- Department of ZoologyStockholm UniversityStockholmSweden
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11
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Haupt A, Minc N. How cells sense their own shape - mechanisms to probe cell geometry and their implications in cellular organization and function. J Cell Sci 2018; 131:131/6/jcs214015. [PMID: 29581183 DOI: 10.1242/jcs.214015] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Cells come in a variety of shapes that most often underlie their functions. Regulation of cell morphogenesis implies that there are mechanisms for shape sensing that still remain poorly appreciated. Global and local cell geometry features, such as aspect ratio, size or membrane curvature, may be probed by intracellular modules, such as the cytoskeleton, reaction-diffusion systems or molecular complexes. In multicellular tissues, cell shape emerges as an important means to transduce tissue-inherent chemical and mechanical cues into intracellular organization. One emergent paradigm is that cell-shape sensing is most often based upon mechanisms of self-organization, rather than determinism. Here, we review relevant work that has elucidated some of the core principles of how cellular geometry may be conveyed into spatial information to guide processes, such as polarity, signaling, morphogenesis and division-plane positioning.
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Affiliation(s)
- Armin Haupt
- Institut Jacques Monod, CNRS UMR7592 and Université Paris Diderot, 15 rue Hélène Brion, 75205 Paris Cedex 13, France
| | - Nicolas Minc
- Institut Jacques Monod, CNRS UMR7592 and Université Paris Diderot, 15 rue Hélène Brion, 75205 Paris Cedex 13, France
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12
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Zhao ZL, Liu ZY, Du J, Xu GK, Feng XQ. A Dynamic Biochemomechanical Model of Geometry-Confined Cell Spreading. Biophys J 2017; 112:2377-2386. [PMID: 28591610 DOI: 10.1016/j.bpj.2017.04.044] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Revised: 04/11/2017] [Accepted: 04/13/2017] [Indexed: 01/09/2023] Open
Abstract
Cell spreading is involved in many physiological and pathological processes. The spreading behavior of a cell significantly depends on its microenvironment, but the biochemomechanical mechanisms of geometry-confined cell spreading remain unclear. A dynamic model is here established to investigate the spreading of cells confined in a finite region with different geometries, e.g., rectangle, ellipse, triangle, and L-shape. This model incorporates both biophysical and biochemical mechanisms, including actin polymerization, integrin-mediated binding, plasma viscoelasticity, and the elasticity of membranes and microtubules. We simulate the dynamic configurational evolution of a cell under different geometric microenvironments, including the angular distribution of microtubule forces and the deformation of the nucleus. The results indicate that the positioning of the cell-division plane is affected by its boundary confinement: a cell divides in a plane perpendicular to its minimal principal axis of inertia of area. In addition, the effects of such physical factors as the adhesive bond density, membrane tension, and microtubule number are examined on the cell spreading dynamics. The theoretical predictions show a good agreement with relevant experimental results. This work sheds light on the geometry-confined spreading dynamics of cells and holds potential applications in regulating cell division and designing cell-based sensors.
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Affiliation(s)
- Zi-Long Zhao
- AML, Department of Engineering Mechanics, Institute of Biomechanics and Medical Engineering, Tsinghua University, Beijing, China; Center for Nano and Micro Mechanics, Tsinghua University, Beijing, China
| | - Zong-Yuan Liu
- AML, Department of Engineering Mechanics, Institute of Biomechanics and Medical Engineering, Tsinghua University, Beijing, China; Center for Nano and Micro Mechanics, Tsinghua University, Beijing, China
| | - Jing Du
- AML, Department of Engineering Mechanics, Institute of Biomechanics and Medical Engineering, Tsinghua University, Beijing, China
| | - Guang-Kui Xu
- International Center for Applied Mechanics, State Key Laboratory for Strength and Vibration of Mechanical Structures, Xi'an Jiaotong University, Xi'an, China
| | - Xi-Qiao Feng
- AML, Department of Engineering Mechanics, Institute of Biomechanics and Medical Engineering, Tsinghua University, Beijing, China; Center for Nano and Micro Mechanics, Tsinghua University, Beijing, China.
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13
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Yang L, Ma Z, Cao C, Zhang Y, Wu X, Lee R, Hu B, Wen L, Ge H, Huang Y, Lao K, Tang F. MR-seq: measuring a single cell's transcriptome repeatedly by RNA-seq. Sci Bull (Beijing) 2017; 62:391-398. [PMID: 36659282 DOI: 10.1016/j.scib.2017.01.029] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Revised: 01/20/2017] [Accepted: 01/20/2017] [Indexed: 01/21/2023]
Abstract
We described a novel single-cell RNA-seq technique called MR-seq (measure a single-cell transcriptome repeatedly), which permits statistically assessing the technical variation and identifying the differentially expressed genes between just two single cells by measuring each single cell twice. We demonstrated that MR-seq gave sensitivity and reproducibility similar to the standard single-cell RNA-seq and increased the positive predicate value. Application of MR-seq to early mouse embryos identified hundreds of candidate intra-embryonic heterogeneous genes among mouse 2-, 4- and 8-cell stage embryos. MR-seq should be useful for detecting differentially expressed genes among a small number of cells.
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Affiliation(s)
- Lu Yang
- Biodynamic Optical Imaging Center, School of Life Sciences, Peking University, Beijing 100871, China
| | - Zhaochun Ma
- Thermo Fisher Scientific, South San Francisco, CA 94080, USA
| | - Chen Cao
- Peking-Tsinghua Center for Life Sciences, Beijing 100084, China
| | - Yuhao Zhang
- Biodynamic Optical Imaging Center, School of Life Sciences, Peking University, Beijing 100871, China
| | - Xinglong Wu
- Peking-Tsinghua Center for Life Sciences, Beijing 100084, China
| | - Raymond Lee
- Thermo Fisher Scientific, South San Francisco, CA 94080, USA
| | - Boqiang Hu
- Biodynamic Optical Imaging Center, School of Life Sciences, Peking University, Beijing 100871, China
| | - Lu Wen
- Biodynamic Optical Imaging Center, School of Life Sciences, Peking University, Beijing 100871, China
| | - Hao Ge
- Biodynamic Optical Imaging Center, School of Life Sciences, Peking University, Beijing 100871, China; Peking-Tsinghua Center for Life Sciences, Beijing 100084, China; Beijing International Center for Mathematical Research (BICMR), Peking University, Beijing 100871, China
| | - Yanyi Huang
- Biodynamic Optical Imaging Center, School of Life Sciences, Peking University, Beijing 100871, China; Peking-Tsinghua Center for Life Sciences, Beijing 100084, China; College of Engineering, Peking University, Beijing 100871, China; Beijing Advanced Innovation Center for Genomics (ICG), Peking University, Beijing 100871, China.
| | - Kaiqin Lao
- Thermo Fisher Scientific, South San Francisco, CA 94080, USA.
| | - Fuchou Tang
- Biodynamic Optical Imaging Center, School of Life Sciences, Peking University, Beijing 100871, China; Peking-Tsinghua Center for Life Sciences, Beijing 100084, China; China Center for Molecular and Translational Medicine (CMTM), Beijing 100101, China; Beijing Advanced Innovation Center for Genomics (ICG), Peking University, Beijing 100871, China.
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14
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Li R, Liu Y, Pedersen HS, Callesen H. Cytoplasmic membrane activities during first cleavage of zona-free porcine embryos: description and consequences. Reprod Fertil Dev 2017; 29:557-564. [DOI: 10.1071/rd15179] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Accepted: 08/26/2015] [Indexed: 11/23/2022] Open
Abstract
Already at first embryo cleavage subsequent blastocyst formation can be predicted based on morphology but the finer morphological details can be difficult to determine due to the presence of the zona pellucida (ZP). Therefore, we monitored zona-free porcine parthenogenetically activated (PA) embryos in a time-lapse system to: (1) describe and characterise the morphological activity of the cytoplasmic membrane and the distribution to the two nuclei during first cleavage and (2) determine the relationship between specific morphological activities and subsequent embryonic development. After ZP removal the membrane surface activities were clearly visible, so all cleaved embryos could be divided into two groups depending on the surface activity during first cleavage: regular morphology (MN) or irregular morphology with ‘bumps’ (MB). The two nuclei were more unequal in MB embryos in both nucleus size and DNA quantity. After first cleavage, MB embryos could be further divided into three types of irregularities (MB1, MB2, MB3) based on their subsequent behaviour. Clear differences in developmental patterns were found between MN and MB embryos, such as delayed first cleavage, compromised blastocyst formation and total cell number. The predictive value of these new types of morphological events was comparable to the more traditionally used time of first cleavage. In conclusion, zona-free embryos allow visualisation of finer morphological details that can provide an early prediction of embryo developmental potential, but further studies are needed on other type of embryos.
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15
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Xu GK, Liu Y, Zheng Z. Oriented cell division affects the global stress and cell packing geometry of a monolayer under stretch. J Biomech 2016; 49:401-7. [PMID: 26774292 DOI: 10.1016/j.jbiomech.2015.12.046] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Revised: 11/25/2015] [Accepted: 12/30/2015] [Indexed: 10/22/2022]
Abstract
Cell division plays a vital role in tissue morphogenesis and homeostasis, and the division plane is crucial for cell fate. For isolated cells, extensive studies show that the orientation of divisions is sensitive to cell shape and the direction of extrinsic mechanical forces. However, it is poorly understood that how the cell divides within a cell monolayer and how the local stress change, due to the division, affects the global stress of epithelial monolayers. Here, we use the vertex dynamics models to investigate the effects of division orientation on the configurations and mechanics of a cell monolayer under stretch. We examine three scenarios of the divisions: dividing along the stretch axis, dividing along the geometric long axis of cells, and dividing at a random angle. It is found that the division along the long cell axis can induce the minimal energy difference, and the global stress of the monolayer after stretch releases more rapidly in this case. Moreover, the long-axis division can result in more random cell orientations and more isotropic cell shapes within the monolayer, comparing with other two cases. This study helps understand the division orientation of cells within a monolayer under mechanical stimuli, and may shed light on linking individual cell's behaviors to the global mechanics and patterns of tissues.
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Affiliation(s)
- Guang-Kui Xu
- International Center for Applied Mechanics, State Key Laboratory for Strength and Vibration of Mechanical Structures, School of Aerospace, Xi׳an Jiaotong University, Xi׳an 710049, China.
| | - Yang Liu
- International Center for Applied Mechanics, State Key Laboratory for Strength and Vibration of Mechanical Structures, School of Aerospace, Xi׳an Jiaotong University, Xi׳an 710049, China
| | - Zhaoliang Zheng
- Stephenson Institute for Renewable Energy, Department of Chemistry, University of Liverpool, Crown Street, Liverpool L69 7ZD, UK
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16
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De Vos A, Abraham M, Franceus N, Haentjens P, Tournaye H, Verheyen G, Van de Velde H. Deposition of the spermatozoon in the human oocyte at ICSI: impact on oocyte survival, fertilization and blastocyst formation. J Assist Reprod Genet 2015; 32:865-71. [PMID: 25925348 PMCID: PMC4491076 DOI: 10.1007/s10815-015-0482-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Accepted: 04/13/2015] [Indexed: 11/26/2022] Open
Abstract
PURPOSE To evaluate whether the deposition of the spermatozoon in the human oocyte at ICSI has any effect on oocyte survival, fertilization, blastocyst development and quality. METHODS In a prospective study, including 78 ICSI cycles, sibling oocytes were injected with "no intention" (group A, standard ICSI, n = 393) or "intention" to deposit the spermatozoon under the cortex (group B, n = 354). Outcome parameters were oocyte survival and fertilization, as well as blastocyst formation and quality. RESULTS Depositing the sperm under the cortex of the oocyte was not always successful for its final position, therefore, group B was divided into three subgroups: B1 successful deposition (119 oocytes, 33.6 % of oocytes in group B); B2 initially successful but spermatozoon spontaneously relocated after 2 min (136 oocytes, 38.4 %); and B3 unsuccessful deposition (99 oocytes, 28.0 %). Group A and B were compared on an intention-to-treat basis. Additionally, A, B1, B2 and B3 were also compared. The oocyte survival and fertilization, blastocyst and top-quality blastocyst developmental rates were not significantly different. CONCLUSIONS The procedure of depositing the spermatozoon intentionally under the oocyte cortex demanded high technical skills. Successful positioning was only obtained in 34 % of the attempts. We obtained no evidence of improved oocyte survival and fertilization, blastocyst formation and quality when the spermatozoon was permanently positioned under the oocyte cortex. Taken together, depositing the spermatozoon under the oocyte cortex is not recommended for routine ICSI application.
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Affiliation(s)
- A De Vos
- Centre for Reproductive Medicine, Universitair Ziekenhuis Brussel, Laarbeeklaan 101, 1090, Brussels, Belgium,
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17
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Wang T, Sha H, Ji D, Zhang HL, Chen D, Cao Y, Zhu J. Polar body genome transfer for preventing the transmission of inherited mitochondrial diseases. Cell 2014; 157:1591-604. [PMID: 24949971 DOI: 10.1016/j.cell.2014.04.042] [Citation(s) in RCA: 108] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2014] [Revised: 03/11/2014] [Accepted: 04/17/2014] [Indexed: 10/25/2022]
Abstract
Inherited mtDNA diseases transmit maternally and cause severe phenotypes. Currently, there is no effective therapy or genetic screens for these diseases; however, nuclear genome transfer between patients' and healthy eggs to replace mutant mtDNAs holds promises. Considering that a polar body contains few mitochondria and shares the same genomic material as an oocyte, we perform polar body transfer to prevent the transmission of mtDNA variants. We compare the effects of different types of germline genome transfer, including spindle-chromosome transfer, pronuclear transfer, and first and second polar body transfer, in mice. Reconstructed embryos support normal fertilization and produce live offspring. Importantly, genetic analysis confirms that the F1 generation from polar body transfer possesses minimal donor mtDNA carryover compared to the F1 generation from other procedures. Moreover, the mtDNA genotype remains stable in F2 progeny after polar body transfer. Our preclinical model demonstrates polar body transfer has great potential to prevent inherited mtDNA diseases.
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Affiliation(s)
- Tian Wang
- State Key Laboratory of Medical Neurobiology, Department of Neurobiology, Institutes of Brain Science, School of Basic Medical Sciences and Department of Neurosurgery, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Hongying Sha
- State Key Laboratory of Medical Neurobiology, Department of Neurobiology, Institutes of Brain Science, School of Basic Medical Sciences and Department of Neurosurgery, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai 200032, China.
| | - Dongmei Ji
- Center for Reproductive Medicine, Department of Obstetrics and Gynecology, the First Hospital Affiliated for Anhui Medical University, Hefei 230022, China
| | - Helen L Zhang
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Dawei Chen
- Center for Reproductive Medicine, Department of Obstetrics and Gynecology, the First Hospital Affiliated for Anhui Medical University, Hefei 230022, China
| | - Yunxia Cao
- Center for Reproductive Medicine, Department of Obstetrics and Gynecology, the First Hospital Affiliated for Anhui Medical University, Hefei 230022, China
| | - Jianhong Zhu
- State Key Laboratory of Medical Neurobiology, Department of Neurobiology, Institutes of Brain Science, School of Basic Medical Sciences and Department of Neurosurgery, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai 200032, China.
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18
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Nestor-Bergmann A, Goddard G, Woolner S. Force and the spindle: mechanical cues in mitotic spindle orientation. Semin Cell Dev Biol 2014; 34:133-9. [PMID: 25080021 PMCID: PMC4169662 DOI: 10.1016/j.semcdb.2014.07.008] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The mechanical environment of a cell has a profound effect on its behaviour, from dictating cell shape to driving the transcription of specific genes. Recent studies have demonstrated that mechanical forces play a key role in orienting the mitotic spindle, and therefore cell division, in both single cells and tissues. Whilst the molecular machinery that mediates the link between external force and the mitotic spindle remains largely unknown, it is becoming increasingly clear that this is a widely used mechanism which could prove vital for coordinating cell division orientation across tissues in a variety of contexts.
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Affiliation(s)
| | - Georgina Goddard
- Faculty of Life Sciences, University of Manchester, Oxford Road, Manchester M13 9PT, United Kingdom
| | - Sarah Woolner
- Faculty of Life Sciences, University of Manchester, Oxford Road, Manchester M13 9PT, United Kingdom.
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19
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Condic ML. Totipotency: what it is and what it is not. Stem Cells Dev 2014; 23:796-812. [PMID: 24368070 PMCID: PMC3991987 DOI: 10.1089/scd.2013.0364] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2013] [Accepted: 12/23/2013] [Indexed: 02/03/2023] Open
Abstract
There is surprising confusion surrounding the concept of biological totipotency, both within the scientific community and in society at large. Increasingly, ethical objections to scientific research have both practical and political implications. Ethical controversy surrounding an area of research can have a chilling effect on investors and industry, which in turn slows the development of novel medical therapies. In this context, clarifying precisely what is meant by "totipotency" and how it is experimentally determined will both avoid unnecessary controversy and potentially reduce inappropriate barriers to research. Here, the concept of totipotency is discussed, and the confusions surrounding this term in the scientific and nonscientific literature are considered. A new term, "plenipotent," is proposed to resolve this confusion. The requirement for specific, oocyte-derived cytoplasm as a component of totipotency is outlined. Finally, the implications of twinning for our understanding of totipotency are discussed.
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Affiliation(s)
- Maureen L Condic
- Department of Neurobiology, School of Medicine, University of Utah , Salt Lake City, Utah
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20
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Abstract
Morphogenesis is the remarkable process by which cells self-assemble into complex tissues and organs that exhibit specialized form and function during embryological development. Many of the genes and chemical cues that mediate tissue and organ formation have been identified; however, these signals alone are not sufficient to explain how tissues and organs are constructed that exhibit their unique material properties and three-dimensional forms. Here, we review work that has revealed the central role that physical forces and extracellular matrix mechanics play in the control of cell fate switching, pattern formation, and tissue development in the embryo and how these same mechanical signals contribute to tissue homeostasis and developmental control throughout adult life.
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Affiliation(s)
- Tadanori Mammoto
- Vascular Biology Program, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts 02115;
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21
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Charnley M, Anderegg F, Holtackers R, Textor M, Meraldi P. Effect of Cell Shape and Dimensionality on Spindle Orientation and Mitotic Timing. PLoS One 2013; 8:e66918. [PMID: 23825020 PMCID: PMC3688943 DOI: 10.1371/journal.pone.0066918] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Accepted: 05/13/2013] [Indexed: 01/13/2023] Open
Abstract
The formation and orientation of the mitotic spindle is a critical feature of mitosis. The morphology of the cell and the spatial distribution and composition of the cells' adhesive microenvironment all contribute to dictate the position of the spindle. However, the impact of the dimensionality of the cells' microenvironment has rarely been studied. In this study we present the use of a microwell platform, where the internal surfaces of the individual wells are coated with fibronectin, enabling the three-dimensional presentation of adhesive ligands to single cells cultured within the microwells. This platform was used to assess the effect of dimensionality and cell shape in a controlled microenvironment. Single HeLa cells cultured in circular microwells exhibited greater tilting of the mitotic spindle, in comparison to cells cultured in square microwells. This correlated with an increase in the time required to align the chromosomes at the metaphase plate due to prolonged activation of the spindle checkpoint in an actin dependent process. The comparison to 2D square patterns revealed that the dimensionality of cell adhesions alone affected both mitotic timings and spindle orientation; in particular the role of actin varied according to the dimensionality of the cells' microenvironment. Together, our data revealed that cell shape and the dimensionality of the cells' adhesive environment impacted on both the orientation of the mitotic spindle and progression through mitosis.
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Affiliation(s)
- Mirren Charnley
- Laboratory for Surface Science and Technology, ETH Zurich, Zurich, Switzerland
- * E-mail:
| | - Fabian Anderegg
- Laboratory for Surface Science and Technology, ETH Zurich, Zurich, Switzerland
| | | | - Marcus Textor
- Laboratory for Surface Science and Technology, ETH Zurich, Zurich, Switzerland
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22
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Piotrowska-Nitsche K, Chan AWS. Effect of sperm entry on blastocyst development after in vitro fertilization and intracytoplasmic sperm injection - mouse model. J Assist Reprod Genet 2012; 30:81-9. [PMID: 23224695 DOI: 10.1007/s10815-012-9896-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2012] [Accepted: 11/18/2012] [Indexed: 12/29/2022] Open
Abstract
PURPOSE To investigate whether in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI), influence the embryo's development and its quality using the mouse as a model. METHODS Assisted fertilization was performed using ICSI and IVF. Fluorescent beads were adhered to the fertilization cone or place of previous sperm injection in the natural mated (NM), IVF and ICSI embryos, respectively. Embryo examination was carried out at the two-cell and blastocyst stage to determine the position of fluorescent bead. Protein expression was detected by fluorescence immunocytochemical staining and confocal microscopic imaging of blastocysts. RESULTS IVF and ICSI embryos developed at rates comparable to NM group. Embryos show similar expression patterns of two transcription factors, Oct4 and Cdx2. The most preferred place for spermatozoa attachment was the equatorial site of the egg, whether fertilization occurred in vitro or under natural conditions. We also link the sperm entry position (SEP) to embryo morphology and the number of cells at the blastocyst stage, with no influence of the method of fertilization. CONCLUSIONS IVF and ICSI, do not compromise in vitro pre-implantation development. Additional data, related to sperm entry, could offer further criteria to predict embryos that will implant successfully. Based on embryo morphology, developmental rate and protein expression level of key transcription factors, our results support the view that ART techniques, such as IVF and ICSI, do not perturb embryonic development or quality.
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23
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Zheng JG, Lu D, Chen T, Wang C, Tian N, Zhao F, Huo T, Zhang N, Chen D, Ma W, Sun JL, Xue P. Label-free subcellular 3D live imaging of preimplantation mouse embryos with full-field optical coherence tomography. JOURNAL OF BIOMEDICAL OPTICS 2012; 17:070503. [PMID: 22894459 DOI: 10.1117/1.jbo.17.7.070503] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Early patterning and polarity is of fundamental interest in preimplantation embryonic development. Label-free subcellular 3D live imaging is very helpful to its related studies. We have developed a novel system of full-field optical coherence tomography (FF-OCT) for noninvasive 3D subcellular live imaging of preimplantation mouse embryos with no need of dye labeling. 3D digitized embryos can be obtained by image processing. Label-free 3D live imaging is demonstrated for the mouse embryos at various typical preimplantation stages with a spatial resolution of 0.7 [micro sign]m and imaging rate of 24 fps. Factors that relate to early patterning and polarity, such as pronuclei in zygote, shapes of zona pellucida, location of second polar body, cleavage planes, and the blastocyst axis, can be quantitatively measured. The angle between the two second cleavage planes is accurately measured to be 87 deg. It is shown that FF-OCT provides a potential breakthrough for early patterning, polarity formation, and many other preimplantation-related studies in mammalian developmental biology.
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Affiliation(s)
- Jing-gao Zheng
- Tsinghua University, Department of Physics and State Key Lab of Low-Dimensional Quantum Physics, Beijing, China
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24
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Liu Z, Hai T, Dai X, Zhao X, Wang Y, Brochard V, Zhou S, Wan H, Zhang H, Wang L, Zhou Q, Beaujean N. Early patterning of cloned mouse embryos contributes to post-implantation development. Dev Biol 2012; 368:304-11. [PMID: 22659081 DOI: 10.1016/j.ydbio.2012.05.027] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2010] [Revised: 05/18/2012] [Accepted: 05/23/2012] [Indexed: 12/20/2022]
Abstract
Several research groups have suggested that the embryonic-abembryonic (Em-Ab) axis in the mouse can be predicted by the first cleavage plane of the early embryo. Currently, it is not known whether this early patterning occurs in cloned embryos produced by nuclear transfer and whether it affects development to term. In this work, the relationship between the first cleavage plane and the Em-Ab axis was determined by the labeling of one blastomere in cloned mouse embryos at the 2-cell stage, followed by ex-vivo tracking until the blastocyst stage. The results demonstrate that approximately half of the cloned blastocysts had an Em-Ab axis perpendicular to the initial cleavage plane of the 2-cell stage. These embryos were classified as "orthogonal" and the remainder as "deviant". Additionally, we report here that cloned embryos were significantly more often orthogonal than their naturally fertilized counterparts and overexpressed Sox2. Orthogonal cloned embryos demonstrated a higher rate of post-implantation embryonic development than deviant embryos, but cloned pups did not all survive. These results reveal that the angular relationship between the Em-Ab axis and the first cleavage plane can influence later development and they support the hypothesis that proper early patterning of mammalian embryos is required after nuclear transfer.
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Affiliation(s)
- Zichuan Liu
- State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
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25
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Predicting division plane position and orientation. Trends Cell Biol 2012; 22:193-200. [DOI: 10.1016/j.tcb.2012.01.003] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2011] [Revised: 01/06/2012] [Accepted: 01/10/2012] [Indexed: 01/06/2023]
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26
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Suwińska A. Preimplantation mouse embryo: developmental fate and potency of blastomeres. Results Probl Cell Differ 2012; 55:141-163. [PMID: 22918805 DOI: 10.1007/978-3-642-30406-4_8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
During the past decade we have witnessed great progress in the understanding of cellular, molecular, and epigenetic aspects of preimplantation mouse development. However, some of the issues, especially those regarding the nature and regulation of mouse development, are still unresolved and controversial and raise heated discussion among mammalian embryologists. This chapter presents different standpoints and various research approaches aimed at examining the fate and potency of cells (blastomeres) of mouse preimplantation embryo. In dealing with this subject, it is important to recognize the difference between the fate of blastomere and the prospective potency of blastomere, with the first being its contribution to distinct tissues during normal development, and the second being a full range of its developmental capabilities, which can be unveiled only by experimental perturbation of the embryo. Studies of the developmental potential and the fate of blastomeres are of the utmost importance as they may lead to future clinical application in reproductive and regenerative medicine.
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Affiliation(s)
- Aneta Suwińska
- Department of Embryology, University of Warsaw, Warsaw, Poland.
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27
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Sperm-borne microRNA-34c is required for the first cleavage division in mouse. Proc Natl Acad Sci U S A 2011; 109:490-4. [PMID: 22203953 DOI: 10.1073/pnas.1110368109] [Citation(s) in RCA: 301] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In mammals, the sperm deliver mRNA of unknown function into the oocytes during fertilization. The role of sperm microRNAs (miRNAs) in preimplantation development is unknown. miRNA profiling identified six miRNAs expressed in the sperm and the zygotes but not in the oocytes or preimplantation embryos. Sperm contained both the precursor and the mature form of one of these miRNAs, miR-34c. The absence of an increased level of miR-34c in zygotes derived from α-amanitin-treated oocytes and in parthenogenetic oocytes supported a sperm origin of zygotic miR-34c. Injection of miR-34c inhibitor into zygotes inhibited DNA synthesis and significantly suppressed first cleavage division. A 3' UTR luciferase assay and Western blotting demonstrated that miR-34c regulates B-cell leukemia/lymphoma 2 (Bcl-2) expression in the zygotes. Coinjection of anti-Bcl-2 antibody in zygotes partially reversed but injection of Bcl-2 protein mimicked the effect of miR-34c inhibition. Oocyte activation is essential for the miR-34c action in zygotes, as demonstrated by a decrease in 3'UTR luciferase reporter activity and Bcl-2 expression after injection of precursor miR-34c into parthenogenetic oocytes. Our findings provide evidence that sperm-borne miR-34c is important for the first cell division via modulation of Bcl-2 expression.
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28
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Rhythmic actomyosin-driven contractions induced by sperm entry predict mammalian embryo viability. Nat Commun 2011; 2:417. [PMID: 21829179 PMCID: PMC3265380 DOI: 10.1038/ncomms1424] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2011] [Accepted: 06/07/2011] [Indexed: 11/22/2022] Open
Abstract
Fertilization-induced cytoplasmic flows are a conserved feature of eggs in many species. However, until now the importance of cytoplasmic flows for the development of mammalian embryos has been unknown. Here, by combining a rapid imaging of the freshly fertilized mouse egg with advanced image analysis based on particle image velocimetry, we show that fertilization induces rhythmical cytoplasmic movements that coincide with pulsations of the protrusion forming above the sperm head. We find that these movements are caused by contractions of the actomyosin cytoskeleton triggered by Ca2+ oscillations induced by fertilization. Most importantly, the relationship between the movements and the events of egg activation makes it possible to use the movements alone to predict developmental potential of the zygote. In conclusion, this method offers, thus far, the earliest and fastest, non-invasive way to predict the viability of eggs fertilized in vitro and therefore can potentially improve greatly the prospects for IVF treatment. Cytoplasmic flows—the movement of cytoplasmic material—can be detected following the fertilization of an egg by a sperm in many species. In this study, rhythmic cytoplasmic flows are shown to be induced in mice by calcium-induced cytoskeleton contractions which could be used to predict the successful outcome of fertilization.
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Littwin T, Denker HW. Segregation during cleavage in the mammalian embryo? A critical comparison of whole-mount/CLSM and section immunohistochemistry casts doubts on segregation of axis-relevant leptin domains in the rabbit. Histochem Cell Biol 2011; 135:553-70. [PMID: 21626127 DOI: 10.1007/s00418-011-0816-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/09/2011] [Indexed: 11/30/2022]
Abstract
Segregation of certain cytoplasmic molecules during cleavage and blastocyst formation that was previously reported to occur in the human and the mouse (Antczak and Van Blerkom Mol Hum Reprod 3:1067-1086, 1997; Antczak and Van Blerkom Hum Reprod 14:429-447, 1999) has been reinvestigated in the rabbit model. Additional methodology was used and two approaches were compared: (1) whole-mount immunohistochemistry followed by confocal laser scanning microscopy (WM-IHC/CLSM) versus (2) IHC performed on histological sections of resin-embedded material (S-IHC). This study concentrates on leptin and cytoskeletal proteins (actin and cytokeratins). With S-IHC, leptin was localized predominantly on the surface of blastomeres which is facing the perivitelline space, and in the extracellular embryonic coats, without any polar asymmetry being detectable along (presumptive) embryonic axes. A polar distribution of leptin with a pattern that could be interpreted as predictive of the prospective embryonic-abembryonic axis was seen only with WM-IHC/CLSM, not with S-IHC, although the latter gave excellent resolution. With both techniques, no differences between blastomeres were detected with respect to actin and cytokeratin patterns, an increased expression of cytokeratin in trophoblast cells occurring no earlier than at blastocyst formation. Artifacts that can occur with the two methodological approaches are critically discussed, as is the possible significance of the findings for theories on the differentiation of trophoblast versus embryoblast and on axis formation in early mammalian development. It is concluded that these data call for cautioning when studying distribution patterns of diffusible molecules with WM-IHC/CLSM technology, whereas patterns obtained with S-IHC are more reliable. Specifically these data cast doubts on previous claims that leptin IHC would allow to monitor cytoplasmic domain segregation occurring during cleavage as an element of early embryonic pattern/axis formation.
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Affiliation(s)
- T Littwin
- Institut für Anatomie, Lehrstuhl für Anatomie und Entwicklungsbiologie, Universität Duisburg-Essen, Hufelandstr. 55, 45122, Essen, Germany.
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Abstract
In the mouse embryo, the first differences between cells that result in distinct lineages have long been thought to arise only as a consequence of differential cell positioning at relatively late preimplantation stages. Differences in Oct4 transcription factor kinetics between cells at the 4-8-cell stage are now shown to be predictive of future lineages, providing further evidence for much earlier initiation of cell fate decisions.
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32
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Control of the mitotic cleavage plane by local epithelial topology. Cell 2011; 144:427-38. [PMID: 21295702 DOI: 10.1016/j.cell.2010.12.035] [Citation(s) in RCA: 144] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2010] [Revised: 11/04/2010] [Accepted: 12/15/2010] [Indexed: 02/07/2023]
Abstract
For nearly 150 years, it has been recognized that cell shape strongly influences the orientation of the mitotic cleavage plane (e.g., Hofmeister, 1863). However, we still understand little about the complex interplay between cell shape and cleavage-plane orientation in epithelia, where polygonal cell geometries emerge from multiple factors, including cell packing, cell growth, and cell division itself. Here, using mechanical simulations, we show that the polygonal shapes of individual cells can systematically bias the long-axis orientations of their adjacent mitotic neighbors. Strikingly, analyses of both animal epithelia and plant epidermis confirm a robust and nearly identical correlation between local cell topology and cleavage-plane orientation in vivo. Using simple mathematics, we show that this effect derives from fundamental packing constraints. Our results suggest that local epithelial topology is a key determinant of cleavage-plane orientation, and that cleavage-plane bias may be a widespread property of polygonal cell sheets in plants and animals.
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Minc N, Burgess D, Chang F. Influence of cell geometry on division-plane positioning. Cell 2011; 144:414-26. [PMID: 21295701 PMCID: PMC3048034 DOI: 10.1016/j.cell.2011.01.016] [Citation(s) in RCA: 256] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2010] [Revised: 11/09/2010] [Accepted: 01/10/2011] [Indexed: 12/31/2022]
Abstract
The spatial organization of cells depends on their ability to sense their own shape and size. Here, we investigate how cell shape affects the positioning of the nucleus, spindle and subsequent cell division plane. To manipulate geometrical parameters in a systematic manner, we place individual sea urchin eggs into microfabricated chambers of defined geometry (e.g., triangles, rectangles, and ellipses). In each shape, the nucleus is positioned at the center of mass and is stretched by microtubules along an axis maintained through mitosis and predictive of the future division plane. We develop a simple computational model that posits that microtubules sense cell geometry by probing cellular space and orient the nucleus by exerting pulling forces that scale to microtubule length. This model quantitatively predicts division-axis orientation probability for a wide variety of cell shapes, even in multicellular contexts, and estimates scaling exponents for length-dependent microtubule forces.
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Affiliation(s)
- Nicolas Minc
- Department of Microbiology and Immunology, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA.
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34
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Clark AG, Paluch E. Mechanics and regulation of cell shape during the cell cycle. Results Probl Cell Differ 2011; 53:31-73. [PMID: 21630140 DOI: 10.1007/978-3-642-19065-0_3] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Many cell types undergo dramatic changes in shape throughout the cell cycle. For individual cells, a tight control of cell shape is crucial during cell division, but also in interphase, for example during cell migration. Moreover, cell cycle-related cell shape changes have been shown to be important for tissue morphogenesis in a number of developmental contexts. Cell shape is the physical result of cellular mechanical properties and of the forces exerted on the cell. An understanding of the causes and repercussions of cell shape changes thus requires knowledge of both the molecular regulation of cellular mechanics and how specific changes in cell mechanics in turn effect global shape changes. In this chapter, we provide an overview of the current knowledge on the control of cell morphology, both in terms of general cell mechanics and specifically during the cell cycle.
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Affiliation(s)
- Andrew G Clark
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany.
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Sharif B, Na J, Lykke-Hartmann K, McLaughlin SH, Laue E, Glover DM, Zernicka-Goetz M. The chromosome passenger complex is required for fidelity of chromosome transmission and cytokinesis in meiosis of mouse oocytes. J Cell Sci 2010; 123:4292-300. [PMID: 21123620 PMCID: PMC2995614 DOI: 10.1242/jcs.067447] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/02/2010] [Indexed: 01/12/2023] Open
Abstract
The existence of two forms of the chromosome passenger complex (CPC) in the mammalian oocyte has meant that its role in female meiosis has remained unclear. Here we use loss- and gain-of function approaches to assess the meiotic functions of one of the shared components of these complexes, INCENP, and of the variable kinase subunits, Aurora B or Aurora C. We show that either the depletion of INCENP or the combined inhibition of Aurora kinases B and C activates the anaphase-promoting complex or cyclosome (APC/C) before chromosomes have properly congressed in meiosis I and also prevents cytokinesis and hence extrusion of the first polar body. Overexpression of Aurora C also advances APC/C activation and results in cytokinesis failure in a high proportion of oocytes, indicative of a dominant effect on CPC function. Together, this points to roles for the meiotic CPC in functions similar to the mitotic roles of the complex: correcting chromosome attachment to microtubules, facilitating the spindle-assembly checkpoint (SAC) function and enabling cytokinesis. Surprisingly, overexpression of Aurora B leads to a failure of APC/C activation, stabilization of securin and consequently a failure of chiasmate chromosomes to resolve - a dominant phenotype that is completely suppressed by depletion of INCENP. Taken together with the differential distribution of Aurora proteins B and C on chiasmate chromosomes, this points to differential functions of the two forms of CPC in regulating the separation of homologous chromosomes in meiosis I.
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Affiliation(s)
- Bedra Sharif
- University of Cambridge, Wellcome Trust and Cancer Research UK Gurdon Institute, Tennis Court Road, Cambridge, UK CB2 1NR
- University of Cambridge, Department of Genetics, Downing Street, Cambridge, UK CB2 3EH
| | - Jie Na
- University of Cambridge, Wellcome Trust and Cancer Research UK Gurdon Institute, Tennis Court Road, Cambridge, UK CB2 1NR
- School of Medicine, Tsinghua University, Beijing 100084, China
| | - Karin Lykke-Hartmann
- University of Cambridge, Wellcome Trust and Cancer Research UK Gurdon Institute, Tennis Court Road, Cambridge, UK CB2 1NR
| | - Stephen H. McLaughlin
- University of Cambridge, Department of Biochemistry, Tennis Court Road, Cambridge, UK CB2 1QW
| | - Ernest Laue
- University of Cambridge, Department of Biochemistry, Tennis Court Road, Cambridge, UK CB2 1QW
| | - David M. Glover
- University of Cambridge, Department of Genetics, Downing Street, Cambridge, UK CB2 3EH
| | - Magdalena Zernicka-Goetz
- University of Cambridge, Wellcome Trust and Cancer Research UK Gurdon Institute, Tennis Court Road, Cambridge, UK CB2 1NR
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36
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37
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Nikitin VA. The tasks and puzzles of cloning. Biophysics (Nagoya-shi) 2010. [DOI: 10.1134/s0006350910030061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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38
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Abstract
Many genes and molecules that drive tissue patterning during organogenesis and tissue regeneration have been discovered. Yet, we still lack a full understanding of how these chemical cues induce the formation of living tissues with their unique shapes and material properties. Here, we review work based on the convergence of physics, engineering and biology that suggests that mechanical forces generated by living cells are as crucial as genes and chemical signals for the control of embryological development, morphogenesis and tissue patterning.
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Affiliation(s)
- Tadanori Mammoto
- Vascular Biology Program, Children's Hospital and Harvard Medical School, Boston, MA 02115, USA
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39
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Abstract
A mature animal body contains a variety of different cell types, and these cells are distributed in a well-organized fashion along the body axes. One of the major questions in developmental biology is how cells acquire different characteristics. In addition, it is important to understand how the embryo forms the body axes and how cells are allocated along these axes during development. Among mammalian species, the molecular mechanisms that regulate embryonic development have been well analyzed and characterized in mice. Here, mouse preimplantation embryonic development is briefly summarized and our current understanding of this complex process based on recent observations is reviewed.
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Affiliation(s)
- Toshihiko Fujimori
- Division of Embryology, National Institute for Basic Biology, Okazaki, Aichi, Japan.
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40
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Abstract
This review describes the three classical models (mosaic, positional, and polarization) proposed to explain blastocyst formation and summarizes the evidence concerning them. It concludes that the polarization model incorporates elements of the other two models and best explains most known information. I discuss key requirements of a molecular basis for the generation and stabilization of polarity and identify ezrin/E-cadherin, PAR proteins, and Cdx2 as plausible key molecular players. I also discuss the idea of a network process operating to build cell allocations progressively into committed differences. Finally, this review critically considers the possibility of developmental information being encoded within the oocyte and zygote. No final decision can be reached on a mechanism of action underlying any encoded information, but a cell interaction process model is preferred over one that relies solely on differential inheritance.
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Affiliation(s)
- Martin H Johnson
- Department of Physiology, Development, and Neuroscience and Center for Trophoblast Research, The Anatomy School, Cambridge CB2 3DY, United Kingdom.
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41
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Martínez-Frías ML. Epidemiology of acephalus/acardius monozygotic twins: new insights into an epigenetic causal hypothesis. Am J Med Genet A 2009; 149A:640-9. [PMID: 19291778 DOI: 10.1002/ajmg.a.32741] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Apart from a series of 10 acephalus/acardius (Ac/Ac) cases described from a pathological point of view, and the analysis of a review of published cases, we have been unable to find any epidemiological studies on Ac/Ac. Using data from the Spanish Collaborative Study of Congenital Malformations (ECEMC), we present here what seems to be the first epidemiological analysis of a consecutive series of the Ac/Ac type of monozygotic twins (MZT). Among a total of 2,281,604 consecutive births, 11 cases of Ac/Ac MZT were detected, giving a frequency of 0.48 per 100,000 births. However, we consider the period 1980-1985 as the baseline for our data, as in this period voluntary termination of pregnancy was not possible in Spain, and the frequency of Ac/Ac MZT was 0.49 per 100,000 births. Nonetheless, this frequency should be considered as a minimal estimation. The characteristics of these Ac/Ac cases indicate that they are more frequent in males (sex ratio 2.67). In addition, gestational age in Ac/Ac cases was 2.41 and 3.12 weeks lower than in malformed and control twins, respectively. Similarly, their mothers are 4.54 and 4.68 years younger than mothers of separate malformed and control twins, respectively. To understand the biological basis behind the occurrence of MZT in the context of recent observations, we evaluate the hypothesis that the epigenetic processes involved in the early cleavage of the embryo, and in blastocyst formation during development, may be implicated in twinning.
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MESH Headings
- Abnormalities, Multiple/embryology
- Abnormalities, Multiple/epidemiology
- Abnormalities, Multiple/genetics
- Anencephaly/embryology
- Anencephaly/epidemiology
- Anencephaly/genetics
- Case-Control Studies
- Databases, Genetic
- Epigenesis, Genetic
- Female
- Heart Defects, Congenital/embryology
- Heart Defects, Congenital/epidemiology
- Heart Defects, Congenital/genetics
- Humans
- Infant, Newborn
- Male
- Models, Genetic
- Pregnancy
- Sex Ratio
- Spain/epidemiology
- Twins, Monozygotic
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Affiliation(s)
- María Luisa Martínez-Frías
- ECEMC, Centro de Investigación sobre Anomalías Congénitas, Instituto de Salud Carlos III, Madrid, Spain.
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42
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Piotrowska-Nitsche K, Yang SH, Banta H, Chan AWS. Assisted fertilization and embryonic axis formation in higher primates. Reprod Biomed Online 2009; 18:382-90. [PMID: 19298738 DOI: 10.1016/s1472-6483(10)60097-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
In naturally fertilized embryos of various organisms, the spermatozoon provides a localized cue to initiate early embryonic patterning. In mice, the sperm entry point (SEP) may reorient the first cleavage division, which separates the zygote into two halves that follow distinct fates. However, it is unknown whether the mechanical injection of spermatozoa into an oocyte by intracytoplasmic sperm injection (ICSI), a technique commonly used in human assisted reproduction, possesses such a role. Rhesus macaque embryos fertilized by ICSI were examined in order to determine the consequences of placing the spermatozoon at specific positions in the ooplasm and whether this can provide new information about patterning in mammalian eggs. The SEP specified by the injected spermatozoa was most often localized near the first cleavage plane and was mainly distributed along the boundary zone that separates the embryonic and abembryonic parts of the monkey blastocyst. Moreover, the ICSI data, when compared with naturally fertilized mouse embryos, showed a similar outcome in terms of cleavage axes and first embryonic axis specification. As there are no studies to date regarding sperm entry in human oocytes and its influence on embryonic development, this investigation using the rhesus macaque as a clinical model is noteworthy.
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43
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Rossant J, Tam PPL. Blastocyst lineage formation, early embryonic asymmetries and axis patterning in the mouse. Development 2009; 136:701-13. [PMID: 19201946 DOI: 10.1242/dev.017178] [Citation(s) in RCA: 428] [Impact Index Per Article: 28.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The investigation into lineage allocation and early asymmetries in the pre- and peri-implantation mouse embryo is gaining momentum. As we review here, new insights have been gained into the cellular and molecular events that lead to the establishment of the three lineages of the blastocyst, to the determination of the origin and the fates of the visceral endoderm in the peri-implantation mouse embryo, and to the generation of cellular and molecular activities that accompany the emergence of asymmetries in the pre-gastrulation embryo. We also discuss the continuing debate that surrounds the relative impacts of early lineage bias versus the stochastic allocation of cells with respect to the events that pattern the blastocyst and initiate its later asymmetries.
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Affiliation(s)
- Janet Rossant
- Research Institute, The Hospital for Sick Children and Departments of Molecular Genetics, and Obstetrics and Gynecology, University of Toronto, Toronto, Ontario, Canada.
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44
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Fujimori T, Kurotaki Y, Komatsu K, Nabeshima YI. Morphological organization of the mouse preimplantation embryo. Reprod Sci 2009; 16:171-7. [PMID: 19208785 DOI: 10.1177/1933719108331120] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
During the 4 days after fertilization, the mouse embryo proceeds in its development within the zona pellucida and reaches the blastocyst stage, when a newly formed embryonic-abembryonic (E-Ab) axis is settled before implantation. The previous findings suggested that the shape of the zona pellucida, which may function as an environmental cue for the embryo proper, is a major factor affecting the specification of the blastocyst axis orientation. The characteristics of the cells were not dependent on the shape of the zona pellucida. It is suggested that the division order of cells is under certain rules, and the differentiation of cells is dependent on the relative position of blastomeres in later stages.
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Affiliation(s)
- Toshihiko Fujimori
- Department of Pathology and Tumor Biology, Graduate School of Medicine, Kyoto University, Sakyo-ku, Kyoto, Japan.
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45
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Müller S, Wright AJ, Smith LG. Division plane control in plants: new players in the band. Trends Cell Biol 2009; 19:180-8. [PMID: 19285867 DOI: 10.1016/j.tcb.2009.02.002] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2008] [Revised: 02/02/2009] [Accepted: 02/02/2009] [Indexed: 01/03/2023]
Abstract
Unique mechanisms are used to orient cell division planes in plants. A cortical ring of cytoskeletal filaments called the preprophase band (PPB) predicts the future division plane during G2 and is disassembled as the mitotic spindle forms, leaving behind a 'cortical division site' (CDS) that guides the placement of the new cell wall (cell plate) during cytokinesis. The molecular features of the CDS have remained elusive for decades. Recently, a few proteins have at last been identified that are specifically localized to or excluded from the CDS and that participate in the orientation, attachment or maturation of cell plates. Recent progress has also been made in identifying proteins needed for PPB formation and thus for division plane establishment.
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Affiliation(s)
- Sabine Müller
- Zentrum für Molekularbiologie der Pflanzen, Universität Tübingen, Auf der Morgenstelle, Germany.
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46
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Gibson WT, Gibson MC. Chapter 4 Cell Topology, Geometry, and Morphogenesis in Proliferating Epithelia. Curr Top Dev Biol 2009; 89:87-114. [DOI: 10.1016/s0070-2153(09)89004-2] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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47
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Jedrusik A, Parfitt DE, Guo G, Skamagki M, Grabarek JB, Johnson MH, Robson P, Zernicka-Goetz M. Role of Cdx2 and cell polarity in cell allocation and specification of trophectoderm and inner cell mass in the mouse embryo. Genes Dev 2008; 22:2692-706. [PMID: 18832072 DOI: 10.1101/gad.486108] [Citation(s) in RCA: 187] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Genesis of the trophectoderm and inner cell mass (ICM) lineages occurs in two stages. It is initiated via asymmetric divisions of eight- and 16-cell blastomeres that allocate cells to inner and outer positions, each with different developmental fates. Outside cells become committed to the trophectoderm at the blastocyst stage through Cdx2 activity, but here we show that Cdx2 can also act earlier to influence cell allocation. Increasing Cdx2 levels in individual blastomeres promotes symmetric divisions, thereby allocating more cells to the trophectoderm, whereas reducing Cdx2 promotes asymmetric divisions and consequently contribution to the ICM. Furthermore, both Cdx2 mRNA and protein levels are heterogeneous at the eight-cell stage. This heterogeneity depends on cell origin and has developmental consequences. Cdx2 expression is minimal in cells with unrestricted developmental potential that contribute preferentially to the ICM and is maximal in cells with reduced potential that contribute more to the trophectoderm. Finally, we describe a mutually reinforcing relationship between cellular polarity and Cdx2: Cdx2 influences cell polarity by up-regulating aPKC, but cell polarity also influences Cdx2 through asymmetric distribution of Cdx2 mRNA in polarized blastomeres. Thus, divisions generating inside and outside cells are truly asymmetric with respect to cell fate instructions. These two interacting effects ensure the generation of a stable outer epithelium by the blastocyst stage.
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Affiliation(s)
- Agnieszka Jedrusik
- Wellcome Trust/Cancer Research UK Gurdon Institute, Cambridge CB2 1QN, United Kingdom
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48
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Van de Velde H, Cauffman G, Tournaye H, Devroey P, Liebaers I. The four blastomeres of a 4-cell stage human embryo are able to develop individually into blastocysts with inner cell mass and trophectoderm. Hum Reprod 2008; 23:1742-7. [DOI: 10.1093/humrep/den190] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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49
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Herr JC, Chertihin O, Digilio L, Jha KN, Vemuganti S, Flickinger CJ. Distribution of RNA binding protein MOEP19 in the oocyte cortex and early embryo indicates pre-patterning related to blastomere polarity and trophectoderm specification. Dev Biol 2008; 314:300-16. [PMID: 18191828 PMCID: PMC2271035 DOI: 10.1016/j.ydbio.2007.11.027] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2006] [Revised: 11/20/2007] [Accepted: 11/21/2007] [Indexed: 11/24/2022]
Abstract
We report the cloning and characterization of MOEP19, a novel 19 kDa RNA binding protein that marks a defined cortical cytoplasmic domain in oocytes and provides evidence of mammalian oocyte polarity and a form of pre-patterning that persists in zygotes and early embryos through the morula stage. MOEP19 contains a eukaryotic type KH-domain, typical of the KH-domain type I superfamily of RNA binding proteins, and both recombinant and native MOEP19 bind polynucleotides. By immunofluorescence, MOEP19 protein was first detected in primary follicles throughout the ooplasm. As oocytes expanded in size during oogenesis, MOEP19 increased in concentration. MOEP19 localized in the ovulated egg and early zygote as a symmetrical spherical cortical domain underlying the oolemma, deep to the zone of cortical granules. MOEP19 remained restricted to a cortical cytoplasmic crescent in blastomeres of 2-, 4- and 8-cell embryos. The MOEP19 domain was absent in regions underlying cell contacts. In morulae, the MOEP19 domain was found at the apex of outer, polarized blastomeres but was undetectable in blastomeres of the inner cell mass. In early blastocysts, MOEP19 localized in both mural and polar trophectoderm and a subset of embryos showed inner cell mass localization. MOEP19 concentration dramatically declined in late blastocysts. When blastomeres of 4- to 8-cell stages were dissociated, the polarized MOEP19 domain assumed a symmetrically spherical localization, while overnight culture of dissociated blastomeres resulted in formation of re-aggregated embryos in which polarity of the MOEP19 domain was re-established at the blastomere apices. MOEP19 showed no evidence of translation in ovulated eggs, indicating that MOEP19 is a maternal effect gene. The persistence during early development of the MOEP19 cortical oocyte domain as a cortical crescent in blastomers suggests an intrinsic pre-patterning in the egg that is related to the apical-basolateral polarity of the embryo. Although the RNAs bound to MOEP19 are presently unknown, we predict that the MOEP19 domain directs RNAs essential for normal embryonic development to specific locations in the oocyte and early embryo.
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Affiliation(s)
- John C Herr
- Center for Research in Contraceptive and Reproductive Health, Department of Cell Biology, P.O. Box 800732, University of Virginia Health System, Charlottesville, VA 22908, USA.
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50
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Bischoff M, Parfitt DE, Zernicka-Goetz M. Formation of the embryonic-abembryonic axis of the mouse blastocyst: relationships between orientation of early cleavage divisions and pattern of symmetric/asymmetric divisions. Development 2008; 135:953-62. [PMID: 18234722 DOI: 10.1242/dev.014316] [Citation(s) in RCA: 110] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Setting aside pluripotent cells that give rise to the future body is a central cell fate decision in mammalian development. It requires that some blastomeres divide asymmetrically to direct cells to the inside of the embryo. Despite its importance, it is unknown whether the decision to divide symmetrically versus asymmetrically shows any spatial or temporal pattern, whether it is lineage-dependent or occurs at random, or whether it influences the orientation of the embryonic-abembryonic axis. To address these questions, we developed time-lapse microscopy to enable a complete 3D analysis of the origins, fates and divisions of all cells from the 2- to 32-cell blastocyst stage. This showed how in the majority of embryos, individual blastomeres give rise to distinct blastocyst regions. Tracking the division orientation of all cells revealed a spatial and temporal relationship between symmetric and asymmetric divisions and how this contributes to the generation of inside and outside cells and thus embryo patterning. We found that the blastocyst cavity, defining the abembryonic pole, forms where symmetric divisions predominate. Tracking cell ancestry indicated that the pattern of symmetric/asymmetric divisions of a blastomere can be influenced by its origin in relation to the animal-vegetal axis of the zygote. Thus, it appears that the orientation of the embryonic-abembryonic axis is anticipated by earlier cell division patterns. Together, our results suggest that two steps influence the allocation of cells to the blastocyst. The first step, involving orientation of 2- to 4-cell divisions along the animal-vegetal axis, can affect the second step, the establishment of inside and outside cell populations by asymmetric 8- to 32-cell divisions.
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Affiliation(s)
- Marcus Bischoff
- MRC Laboratory of Molecular Biology, Hills Road, Cambridge, UK
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